diff --git a/README.md b/README.md
index 1f316a3..717c288 100644
--- a/README.md
+++ b/README.md
@@ -13,3 +13,11 @@ to do:
 * make more efficient
 
 training_data/test_data not included
+format: json: 
+[{"x":[float;784], "y": u32}]
+=> x: 28x28 gray image as float
+=> y: label 0.. 9
+
+the data can be found here:
+https://github.com/mnielsen/neural-networks-and-deep-learning/blob/master/data/mnist.pkl.gz
+albeit in a different format
\ No newline at end of file